Henry’s Fork

Henry’s Fork, September 14th, 2024

Below the Ora Bridge

The recent unsettled weather and that upcoming next week is just what is needed to bring on the fall mayfly emergence peak (BWO, mahogany dun) throughout the river. Some of these are mayflies are appearing up and down the river, but ants and hoppers remain the main reasons for great top water fishing. Upcoming cooler weather along with diminishing daylight hours will also break up aquatic vegetation making subsurface fly fishing, whether through “nymphing” or presenting streamers more widespread.

Henry’s Fork, September 7th, 2024

At Last Chance

Small nymph patterns work well in Box Canyon especially when such are under your favorite grass hopper pattern. During evenings, switch to streamer patterns where there is deeper water. Ant and hopper patterns cannot be beat for action in the Last Chance-Harriman portion of the the river especially during daytime hours. Water temperatures are no longer a concern thanks to cooler nights and shortening day time hours. A few mahogany duns are appearing with peak numbers yet to come. The lower river needs more cooling weather to offer its best fishing. That may begin soon as unsettled weather is expected later this week.

Henry’s Fork, September 4th, 2024

At about 550 cfs is coming out of Island Park Dam, so flow in the river below is about two-thirds of normal. That means the Last Chance-Harriman reach demands stealth, long leaders and fine tippets.  This finest of equipment makes it tough on fish played to possession then released no matter how cool the water.  The bigger the fish the tougher it is for them to recover from being caught and played when fine leaders and tippets are used. So take all the time needed to revive them.  Don’t forget those ant patterns!

Henry’s Fork, August 31st, 2024

Flying ants

Cooler nights and less daylight will help bring the lower river around to water temperatures more suitable for lower river trout to survive the rigor of catch and release. September is perhaps the most pleasant month to fish anywhere on the river. Fewer anglers are present.The fall mayfly emergence peak, PM caddis activity, and terrestrial insect (especially flying ants!) population make top water fishing wonderful. Presenting streamer patterns during low light conditions on the lower river, Box Canyon or the Tubs will become increasingly effective the further we move into autumn.

Henry’s Fork, August 28th, 2024

 Watch crowds of  fly fishers diminish on the upper river after Labor Day.  Back to school and the end of vacations along with fewer insect pests make September the most pleasant month to fish this part of the river.  The Fall mayfly peak will be in progress with trico, tiny BWOs and mahoganies. Gone are the concerns of low dissolved oxygen, and the days of dense aquatic vegetation are numbered.

Flies to fish:

• Harrop’s D & D Cripple Mahogany
• Antonio’s Adult BWO
• CDC Trico Spinner

Henry’s Fork, August 24th, 2024

Flow out of Island Park Dam is a bit below seasonal amounts.  Cloudy conditions with some thundershowers continue in keeping water temperatures below dangerous
levels for salmonids. Early AM trico activity continues, and ant patterns are becoming increasingly effective. If weather begins to cool, trout activity on the lower river will begin.  A sign
of  this return will the appearance of tiny BWOs during afternoon hours.

Henry’s Fork, August 17th, 2024

Because of cooler late summer air and less daylight, we are past the dissolved oxygen and water temperature concerns of the year for the upper river. This means that catch and release fishing throughout the day generally will not stress subjected salmonids. So beginning with the AM trico activity on to when terrestrial insects, speckled dun mayfly and caddis fly activities take over, enjoy what the river offers

( be sure to have flying ant patterns in that fly box ). It will be a few weeks before these thoughts apply to the lower river.

A UNIQUE TOUR AVAILABLE AUGUST 20

Every year, the Henry’s Fork Watershed Council hosts a “Watershed Tour”. Participants visit sites within the watershed where water issues or key projects are occurring. This year, the tour will focus on Island Park Reservoir, Island Park Dam, and Last Chance Wastewater Treatment Plant to discuss the theme of water quality in the Henry’s Fork Watershed. The reservoir portion of the tour will be conducted via pontoon boat, so participants must RSVP to [email protected] to reserve a spot. The tour is scheduled to run from 9 AM – 3 PM, Tuesday, August 20th. For more information, please email [email protected].

Henry’s Fork, August 13th, 2024

 Flow out of Island Park Dam is at seasonal amounts but reservoir volume is a bit below normal.  There can some good fishing on the west end around such as Grizzly Springs. Try red midge pupa patterns under an indicator to find the taking depth.  Cloudy conditions with some thundershowers have helped in keeping water temperatures below dangerous levels for salmonids. Early AM tricos make up the “name of the mayfly game.”  After this diminishes about mid-day, presenting ant and hopper patterns can bring action.  As we move through August, flying ants will increase in numbers and will be sought by trout especially along the upper river.

Flies to fish:

• Red Mirage Zebra Midge
• Indicator Para Trico
• Chubby Cubby-Brown

Henry’s Fork, August 10th, 2024

The effects of water temperature and dissolved oxygen on salmonid well being will begin to wind down now with less daylight coming through shorter days and cooler nights as we move through August. Cooler air temperatures and less daylight means more active trout. The river from Island Park Dam to Pinehaven is a good example of this coming on. Early in the day trico activity is the major mayfly event up and down the river now with some speckled duns coming out in slow water reaches. Terrestrial insect patterns, especially those for ants and hoppers will produce later in the day as will those for the caddis life cycle.

Flies to fish:

• CDC Trico Spinner
• Unsinkabeetle-Black